Isara is a tall woman with long blonde hair and brown eyes. A black headband is worn in her hair. Isara dresses in a black crumpled top with a green waistcoat and blue blazer, complete with cream trousers and black high-heeled shoes. She wears a number of accessories including bangles, a pendant and a pair of bright green earrings.
Isara is a confident woman and not afraid to call out and backchat others. She cares a lot for her brother and sister, stating that she isn't one to talk when stating Claire is the same way. The Rieveldt Company means a lot to her and she does her best to keep it running through her consultancy.
Isara is a daughter of the Vice-President of the Rieveldt Company. They were always very close to the other Rieveldt family until the accident that took the lives of Claire's father, mother and little brother, Emil. After that Claire was taken in to their family and Isara was a smaller sister to Claire.
Claire soon discovered and exposed her uncle's scheme in which Isara's father was selling low-quality Rieveldt products as premium ones, which Claire's father had tried to stop. Following the scandal, her mother decided to drop "Rieveldt" in favor of "Irving", with her children following suit.
Isara took up employment with a managing consultancy, and does business with the current owners of the Rieveldt Company.
Isara travels to Heimdallr to meet with Morgan at the Rieveldt Company, by chance meeting Claire whilst in the city, and brushing off Sara Valestein whilst she talks with her sister. After concluding business with Morgan, Isara expresses the company is precious to her before leaving. It starts to rain and she considers calling her brother Michael at Leeves. Isara witnesses the Simulacrum of the Emperor whose camouflage is affected by the rain, and he decides to abduct her to leave no witnesses. Isara only just manages to call Michael for help before she is taken. Claire's group locate and confront the Emperor in the catacombs, forcing him to retreat while they tend to Isara. She comments that Claire is too obsessed with her brother and sister, but that she isn't one to talk. Isara thanks and apologizes to Claire.
Later, she chats with Michael on the phone and accepts the position he mentioned to her. She turns up at Thors Branch Campus and is the new military finance instructor with Towa Herschel being the new chief instructor, taking over from Michael who is returning to the RMP. Isara commands the Derfflinger when it arrives at Reverse Babel for the final battle.